Receptor Dimerization Assay Services
Choosing the right primary high-throughput screening assay for G-protein-coupled receptors (GPCRs), one of the most important protein families for therapeutic targeting, is critical in early drug discovery. GPCR dimerization may direct the localization of downstream signaling components to specific areas of the cell. It may be a mechanism to aggregate downstream signaling components, thus facilitating greater amplification in signaling. Creative Biolabs is diverse, knowledgeable, and agile, with a solid leadership universally recognized in the world of GPCR drug discovery. We have expertise and capabilities in providing high-quality receptor dimerization assay.
Overview of Receptor Dimerization Assay
The dimerization of GPCRs can be observed in the early stage after biosynthesis and has a profound influence on the pharmacological action and signal transduction of the receptor. The compounds specifically targeting GPCR heterodimers or affecting receptor dimerization may have the potential to achieve specific therapeutic effects. It is of great interest to design analytical methods to evaluate the effect of compounds on GPCR dimerization. Various techniques have been established to monitor receptor dimerization, where donor and acceptor molecules are genetically fused to the C-terminus of GPCRs, which are overexpressed in cells in the commonly used fluorescence resonance energy transfer (FRET) or bioluminescent resonance energy transfer (BRET)-based approaches. Resonant energy transfer occurs when donor and acceptor molecules are brought close to the GPCR dimer as a result.
Fig.1 Receptor dimerization assays. (Cechova, 2021)
Roles of G-protein-coupled Receptor Dimerization
Heterodimerization of GPCRs could modulate receptor function by regulating ligand binding properties, signaling as well as receptor trafficking properties.
- Ontogeny: GPCRs exit from the endoplasmic reticulum (ER) is a crucial step that controls their cell surface expression. Only correctly folded receptors are removed from the ER quality control system and allowed to exit.
- Ligand-promoted Regulation: once in the plasma membrane, dimers may be targets for dynamic regulation through ligand binding.
- Pharmacological Diversity: it has been proposed that GPCR heterodimerization leads to both positive (+) and negative (-) ligand binding cooperativity.
- Signal Transduction: GPCR dimerization has a crucial function in signal transduction.
- Internalization: heterodimerization can promote the co-internalization of two receptors after the stimulation of only one protomer.
Fig.2 Potential roles of GPCR dimerization during the GPCR life cycle. (Terrillon, 2004)
Techniques Used to Identify G-protein-coupled Receptor Dimers
- Pharmacological Methods
Pharmacological studies provided the first indirect evidence for the presence of GPCR dimers. Complex radioligand-binding data demonstrating either positive or negative cooperativity hinted at the possibility of physical interactions between receptors.
- Biochemical Methods
To examine the physical interactions between GPCRs, radiation inactivation (target size analysis) was used. This technique is based on an inverse relationship between the size of macromolecules and the dose-dependent inactivation of ionizing radiation.
- Biophysical Methods
To determine whether GPCR dimers are present in living cells, biophysical techniques have been used to observe protein-protein interactions in situ. FRET and BRET techniques have been used to directly visualize GPCR dimers in living cells.
GPCR dimer may be a new target for rational drug design and the development of new drug delivery regimens. Creative Biolabs’ experts can help you from the very first idea, by providing expert consultancy in the design of your study. We are happy to discuss your objectives. Please feel free to contact us to discuss your GPCR drug discovery project.
References
- Cechova, K.; et al. Kappa but not delta or mu opioid receptors form homodimers at low membrane densities. Cellular and Molecular Life Sciences. 2021, 78(23): 7557-7568.
- Terrillon, S.; Bouvier, M. Roles of G-protein-coupled receptor dimerization: From ontogeny to signaling regulation. EMBO reports. 2004, 5(1): 30-34.
